Question

Marathon runners were randomly assigned to receive either vitamin C or a placebo.

Separately, these treatments were also randomly assigned to a group of nonrunners the same age as the runners. All subjects were watched for 2 weeks after the race to see if infections developed.

1. What is the name for this experimental design? I think it is either randomized comparative design or compeltely randomized design. Can you please explain and help me out? Thank you

Answer 1

Could it be a block design?

Thank you

Answer 2

Yes.